Improved method for destructive hydrogenation of carbonaceous materials



Jan. 17, 1933. J. M. JENNINGS IMPROVED METHO DESTRUCTIVE HYDROGENATIONOF CARBONRCEOUS MATERIALS Filed Dec. 21, 1928 WW \N Patented Jan. 17,1933 UNITED STATES PATENT OFFICIE JAMES M. JENNINGS, OF BATON ROUGE,LOUISIANA, ASSIGNOR T STANDARD-I. G. COMPANY METHOD FOR DESTRUCTIVEHYDROGENATION OF CARBONACEOUS MATERIALS The I resent invention relatesto improvements in the art of destructive hydrogenation of carbonaceousmaterials and more specifically comprises an improved method forcarrying out the destructive hydrogenation process for relatively long,practically in-' definite, periods. My invent-ion will .be fullyunderstood from the following description and the drawing whichillustrates an apparatus constructed for that purpose.

The drawing is a semi-diagrammatic view in sectional elevation of anapparatus for destructive hydrogenation of carbonaceous materialsaccording to my invention.

Referring to-the drawing, reference character 1 designates a reactionchamber or drum adapted to withstand pressures. of 200 atmospheres orhigher at a temperature of about 1000 F., as well as the corrosiveaction of the reactants. The drum is suitably protected against loss ofheat by insulation 2 and may be heated in any suitable manner,

such as electrically, but I prefer to maintain the temperature of thedrum by withdrawing a part of its contents by pipe 3 and forc ing it bythe action of a suitable pump 4 through a coil 5 arranged in a furnacesetting 6.. Heated material is discharged from coil 5 through line 7back into drum 1.

Hydrogen or a gas rich in free hydrogen is fed from a supply pipe 8 intobranch pipe 9 which communicates with the inlet of coil 5. Hydrogen mayalso be fed from pipe 8 into drum 1 by pipe 10. i

Vapor and gas leave drum 1 by a vapor pipe 11 and flow through heatexchangers 12 and 13 before discharge to condenser 14 and separationdrum 15. Distillate is removed from drum 15 by line 16 to storage snotshown) or to stills for removing low boi ing components from heavieroils which may be returned as feed to drum 1, as will be understood.

Fixed gas from drum 15 is passed by line 17 through two towers 18 and 19in series for purification. Tower 18 is fed with oil by pump 20 and line21 and oil saturated with gaseous or low boiling hydrocarbons is removedby line 22. Tower 19 is fed with an aqueous soda solution'or the likefor removal Application filed December 21, 1928.

Serial N0. 327,498.

of hydrogen sulphide. The solution is forced through pipe 24 by pump 23and is discharged by line 25. Purified gas then fiows by line 26 tobooster pump 27 and is returned to feed line 8 by line 28, beingpreheated by passage through exchanger 12.

Fresh hydrogen or a gas rich in the same enters the system by pipe 29and gas may be bled from the system by pipe 30.

Feed oil enters by pipe 31 and is forced by pump 32 through exchanger 13and flows by lines 33 and 34: to line 3; Line 3 is fitted with a valvedsampling line 85 and a drum 36 is connected to lines 33 and 3 by valvedlines 37 and 38 for introduction of fresh catalyst, as will bedescribed. A valved line 35' is provided connecting the upper part ofdrum 36 with circulation line 3.

In the operation of my process crude oils, reduced crudes, and otherpetroleum cuts may serve as the feed stock and other carbonaceousmaterial such as tars, cracked residues, or a suspension of pulverizedcoal in oil, may be used. Such carbonaceous material is converted to lowboiling oil under pressure of hydrogen inexcess of about 25 atmospheres,although I prefer to use about 200 atmospheres and temperatures from 800to 970 F. Hydrogen is continuously fed to the drum 1 and vapors arecontinuously removed. Catalysts such as chromium and molybdenum oxidesor the like which are not susceptible to sulfur poisoning may besuspended in the oil to increase the rate of hydrogenation. Suchcatalysts as these which retain their hydrogenating activity in thepresence of sulfur or sulfur-containing compounds are aptly termedsulfactive. I have found in the operation of the above systems,particularly on heavy asphaltic materials, that there is asteadyincrease of asphalt which necessitates short runs due to coke formation.I have also discovered that in order to insure steady continuousoperation without danger of plugging by excessive coke formation,theratio of asphalt to catalyst in the body of material being treatedshould be maintained below about .5 as determined below. The ratioshould never be allowed to rise above about 1.0 or 1.5

since it is then impossible to prevent coke formation in a few hourseven by addition of fresh catalyst. .The suspension, of course. mustalways be free-flowing. 1

When operating on oil or other ash-free hydrocarbon material, samples ofthe suspension in the drum are withdrawn at intervals of an hour ormore. The sample may be taken from thedrum or; from the circulation lineby pipe 35. A 10 cc. sample is first filtered and the residue is washedwith naphtha to a constant weight which represents total solids in thesample. This residue is then washed with benzol or other solvent capableof dissolving asphalt to a constant weight which represents the catalystin the sample. The difference between total solids and catalyst is takenas asphalt. If the ratioof asphalt to catalyst is above about .5, asuitable quantity of powdered catalyst calculated to restore the properratio is introduced into drum 36. The normal flow of oil from line 33through line '34 and into line 3 is then diverted by manipulation ofproper valves so that part of the oil passes through drum 36 carryingthe catalyst into the circulation system.

If an ashy material such as coal is being treated as a suspension-inoil, the procedure must be changed to allow for the ash and coal in thesample which will remain undissolved bv benzol and appear as catalyst inthe a ove described testbut which should not be included in determiningthe ratio above described. Correction for the ash and coal in the samplemay be made by chemical analysis of the asphalt free residue or by'calculation ofthe amount of ash in the system, as will be understood.

To prevent accumulation of ash in the system, the recirculated materialmay be withdrawn at intervals by use of lines 35 and 37 and drum 36 orcontinuously by suitable lines (not shown).

As an example of the operation of my process, the following runs aregiven on topped Crane-Upton crude oil of 23.5 A. P. I. The temperatureof the oil is 850 F., the pressure 3000 pounds per square inch in bothruns, and a gas rich in free H is circulated at the same rate andlargely in excess of that quantity required for reaction with the oil.The distillation rate in each case is approximately the same and bothdistillates contains about 22% of material boiling below 374 F. In onerun, the ratio of asphalt to catalyst is maintained below about .5. Thisis accomplished, as above described, by the addition of catal st fromtime to time. The run proceeds or about 300 hours without any indicationof coke formation. In a second run, no attempt is made to maintain theproper ratio of asphalt o catal st and after the fifth hour, the ratiois a out 1.0. The run is discontinued after the thirteenth hour when itis evident that the apparatus first run is approximately 20%, and in thesecond run about 10%. The catalyst in each case hhs the samecomposition.

My process is not to be limited by any theory of the mechanism of theprocess nor by any illustrative example given merely by way ofillustration but only by the attached claims in which I wish to claimall novelty inherent in my process.

I claim:

1. An improved process for the destructive hydrogenation of heavyasphalt-containing materials, comprising maintaining a body of suchmaterial at decomposition temperature in the presence of hydrogen underhigh pressure and in contact with a solid catalyst resistant to sulfurpoisoning suspended in the material and holding the ratio of asphalt tocatalyst below about 1.5.

2. An improved process for the destructive hydrogenation of heavyasphalt-containing materials, comprising maintaining a body of suchmaterial under temperature between the approximate limits of 800 and 970F. and under a hydrogen pressure in excess of 25 atmospheres in .thepresence of a and holding the ratio of asphalt to catalyst below about.5.

3. Process according to claim 2, in which vapors are continuouslyremoved from the body of material undergoing decomposition.

4. Process according to claim 2, in which fresh catalyst is added to thebodyof material 'at intervals whereby the limiting ratio of asphalt tocatalyst is maintained.

5. Process according to claim 2, in which heav asphalt-containingmaterial is continuousiy withdrawn from the body of material undergoingdecomposition, heated, and returned to the body.

6. Process according to claim 2, in which fresh. heavyasphalt-containing material is continuously forced into the body ofmaterial undergoing decomposition through a fresh feed line and in whichfresh catalyst is added from time to time by placing it in a closedvessel, connecting said vessel into the fresh feed line and passing thefresh feed through said vessel and into the body of material undergoingdecomposition.

7. An improved process for the destructive hydrogenation ofasphalt-containing hydrocarbon oil which comprises suspending in the oila sulfactive catalytic material, forcing the suspension into a reactionzone maintained at a decomposition temperature and under pressure ofhydrogen in excess of 25 atmospheres sufiicient to keep higher boilingconstituents in liquid phase, maintaining the ratio of asphalticconstituents to catalyst in tinuously removing lower boilingconstituents formed in the reaction. I

8. Process according to claim 7, in which the reaction zone ismaintained at a temperature within the approximate range of 800 to 970F. and the lower boiling constituents are continuously removed in vaporform.

9. Improved process for the destructive hydrogenation of heavyasphalt-containing hydrocarbon oil which comprises suspending in the oila sulfactive catalyst comprising metal oxides, forcing the suspensioninto .a reaction zone maintained ,at a temperature between 800 and 970F. and under pressure of hydrogen in excess of 25 atmospheres sufficient to hold the heavier constituents in liquid phase, continuouslyremoving a stream of suspension from the reaction zone, heating the samein admixture with hydrogen, returning the heated mixture to the reactionzone, and continuously maintaining the ratio of asphaltic materials tosuspended catalyst inthe reaction zone below about .5.

10. In the hydrogenation of fluent carbonaceous material under pressureof hydrogen between 25 and 200 atmospheres at temperatures between 800and 970 F. and in the presence of finely divided sulfactive metal oxidessuspended in the carbonaceous material, the improvement which comprisesmaintaining the ratio of heavy asphaltic materials formed in thehydrogenation to metal oxides below about 1.5, while the materials areunder reaction conditions.

JAMES M. JENNINGS.

